initialization viewcontroller by : http://napora.org/nscoder-and-swift-initialization/

gistfile1.swift

class FooViewController: UIViewController {  
  let name: String

  init(_ coder: NSCoder? = nil) {
    name = "Bar"

    if let coder = coder {
      super.init(coder: coder)
    } else {
      super.init(nibName: nil, bundle:nil)
    }
  }

  required convenience init(coder: NSCoder) {
    self.init(coder)
  }
}